Aneroid barometer



S. G. STARLING AND A. J. HUGHES.

ANERom BAROMETER. APPLICATION FILED DEC- 23| l9l8.

1,377,032. l Patented May 3, 1921.

l I ,/mwmm UNITED srAa'rEsPATENr oFFlcle..A

SYDNEY GEORGE STARLING, OF FOREST GATE, AND ARTHUR JOSEPH HUGHES, .OFLONDON, ENGLAND, ASSIGNORS T0 HENRY HUGHES AND SON LIMITED, OF LONDON,ENGLAND, A CORPORATION OF` ENGLAND. l

ANERoID BAROMETER.

Specication of Letters Patent. Patented May 3, 192.1.

Application :filed December 23, 1918. ,Serial No. 268,062.

To all whom t may concern.'

Be it known that we, SYDNEY GEORGE STARLING, of 6l Windsor road, ForestGate, in the county of Essex, England, and AR- THUR JOSEPH HUGHES, of5,9 Fenchurch street, in the city and county of London, England, bothsubjects of the King of Great Britain, have invented a new and usefulImprovement in and Relating to Aneroid Barometers, of which thefollowing is a specification.

, This invention relates to aneroid barometers or altlmeters formeasuring the barometrie pressure, or height above earth by means ofbarometric pressure, and it has for its object an improvedconstructionof the vacuum box and of the mechanism andcalibrating oradjusting system of the aneroid.

According' to our invention the free or movable face of the vacuum boxis provided with a plane surface on. which rests a point on a pivotedlever that is in sliding contact with the surface of a pivotally mountedcam preferably connected .to the pointer of the instrument through awheel or quadrant having fixed to it one end of a cord that rests on theperiphery of the wheel or quadrant and is wound around a drum fixed onthe pointer-spindle, the other end of the 'cord being secured to atensioning spring.

By suitably shaping the cam, any desired relation can be obtainedbetween the angle moved through by the pointer and the variation in thepressure of the atmosphere on the 'walls of the vacuum box, c. g., equalangles moved through by the pointer may correspond to equal incrementsor decrements ofY pressure, or to equal increments or decrements ofaltitude.

In order to reinforce the movable walls of the vacuum box, a light pieceof steel spring is fitted across the same, preferably so as to extendaround both sidesof the box.` By' lvarying the strength of thlsspringand the degree of vacuum in the box, the instrument can be adapted tomeasure any desired range of pressures or altitudes.

In the accompanying drawing we have shown how our said invention may beconveniently and advantageously carried into practice.

In this drawing Figure 1 is a side elevation partly in vertical centralsection, and

-mo'vable wall of the vacuum box.

Fig. 2 a pla-n with parts removed showing an instrument constructedaccording to our lnvention. y

Fig. 3 is a partial side elevation looking at right angles to the viewin Fig. l.

The vacuum box A is constructed in the usual way and mounted on the baseplate B of the instrument, a lightv piecevC of steel springk beingfitted to extend around the vacuum box A, across a diameter thereof. Theends of the spring are secured to a block B on the base plate B, and theupper middle part is secured to the vcenter ofthe upper This spring maybe varied in strength according to the scale of pressure to be measuredand the extent of vacuum created in the box.

In the center of the vacuum box, on the upper face,'andon the top of themiddle of the spring b, there isitted'a disk D of steel, glass,sapphire, or the like having a polished flat upper surface, and on theplane thus formed there rests a small agate point E attached to thecenter o f a steel arm or lever F which is pivoted at F in a brassstandard G. The other end of the arm is provided with a lateral pin Hbearing against a cam surface J formed on a quadrant -`K pivoted at K tothe standard G and on the periphery of .which a groove is cut to receivea fine thread or cord L of metal, fiber, silk, or other suitablematerial. This Cord is stretched from the quadrant K to thepointer-spindle M which is centrally mounted in suitable bearings in aframe member N, and carries an indicating pointer O movablearoundthe-scale of a dial P indicating barometric pressure or heightaccord-l ing to the particular type of instrument. One end of the cord Lbeing attached to the groove in the quadrant K, the said cerdas threadedthroughthe spindle M, andethe two lends are wound several times aroundthe latter, and the free end of said cord is carried across and abovethe vacuum box and is attached to a tension spring Q, connected to thestandard G, whereby the cord is kept taut and the return of theindicating pointer to the initial vposition is insured.

The cam J 'is formed to a curve suitably calculated to roduee a lscaleof pressure or height according to requirement, e. g., a scale in whichequal angles indicate equal increments or decrements of pressure orheight.

In operation, when the instrument is subjected to change in pressure,the vacuum box A will lcontract or expand and by the interaction of thepolishedv center plate D and the agate point E, a corresponding movementof the lever F is produced so that the pin H at the other extremity ofthe lever F actuates the quadrant, the cord in the groove of the latterbeing carried backward or forward and the central spindle M [with itspointer O being accordingly moved to a like extent.

The dial P is shown rotatably mounted in an annular channel S inthecasing T and is provided with peripheral teeth to enable it to vberotated by means ofxa pinion U. This pinion is mounted to turn inbearings in the flange T ofthe casing T and is provided with a milledhead V. I

What we claim as our invention and desire to secure by Letters Patent,is

l. An aneroid barometer comprising a vacuum box, a lever 1n operativerelatlon y with said vacuum boxu and adapted to -be to said vacuum boxmovable in response tol variations in the barometric pressure as thelatter 4aects said box, a segment .pivoted diaphragm, a needle tionedblock, a lever carrying said needle,'

a single cam surface extending along one edge thereof and` adapted torest upon the free end of said lever whereby the segment y will be movedby the lever, pivoted indicating means, and a flexible connectionbetween said indicating means and the segment, substantially asdescribed.

3. An laneroid barometer comprising a near vthe free end of said leverand having x casing, a vacuum box supported within the casing, a blockbeneath the vacuum; box, a fiat spring having its ,free ends `tted insaid block, said spring extending diametrically about said vacuum boxand being in engagement with the central part of the diaphragm thereof,a block supported upon the spring at the portion at which it makescontact with the gaging said last mensupporting posts within saidcasing, one of said posts having a fulcrum for said lever, a` segment.pivoted in the other post and adapted to swing vertically, said segmenthaving a cam face along. one 'radial edge, means on the free end of-thevlever, cop` erating with the camface of the segment, -a scale in theupper part of the casing, an indicator moving over said scale, a shaftfor the indicator, a flexible connection wound intermediately aboutsaidshaft and having. one end connected to said segment, and

spring means connecting the other end of said connection with one ofsaid posts, substantially Aas described.

SYDNEY GEORGE STARLING. v

ARTHUR JOSEPH HUGHES.V

